Tube-coating apparatus



May 29, 1928.

C. F. MOORE ET AL TUBE COATING APPARATUS Fild July 16, 1925 2Sheets-Sheet 1 lllllllllll Zi M3 C. F. MOORE ET AL TUBE COATINGAPPARATUS May-29, 1928. 1,671,374

Filed July 16, 1925 2 Sheets-Sheet '2 7 mun'lum 83 ouirrn srATa CHARLESF. MOORE AND CHARLES E. STUBBS, OF BOSTON, MASSACHUSETTS, AS-

SIGNORS TO THE DAMPNEY COMPANY OI AMERICA, OF

A CORPORATION OF MASSACHUSETTS.

BOSTON, MASSACHUSETTS,

I TUBE-COATING APPARATUS.

Application m a m 16, was. serial no. 43,962.

This invention in general relates to apparatus for applying a protectivecoating to the inside of boiler tubes and the like, and

its object is to provide an apparatus where I by the interior of thetubes may be coated,

in the nature of a painting operation, uniformly, efficiently, quicklyand conveniently, and with a minimum amount of labor.

To these ends we provide a rotary brush and an air turbine adapted toenter the tube, and a source of compressed air and a moisture remover,conveniently located, connected with the air turbine by means of acomparatively stout, flexible, air conduit.

In the accompanying drawings,

Figure 1 is a general view of the apparatus, showing the brush and airturbine Fig. 5 is a sectional view of the air turbine taken on the line5-5 of Fig. 2, looking in the direction indicated by the arrows;

Fig. 6 is a sectional view of the air turbine taken on the line 6.6 ofFig. 2, looking in the direction indicated by the arrows; Fig. 7. is apartial sectional view of the air turbine taken on the line 77 of Fig.2,

looking downwardly; and v a t Fig. 8 is a sectional view taken on theline 8-8 of Fig. 2, looking in the direction indicated by the arrows.

Referring now to the drawings in detail,

40 in which like reference numerals designate similar parts throughoutthe several views,

10 denotes a boiler tube expanded atone end into the end plate 11. 1 Thetube is prepared for the coating operationgby being thoroughly cleanedof foreign matter and in crustation's on the inher periphery of 'thetube. Then the coating, in liquid form, in

proper amount taking into consideration the lengthand diameter of thetube, is poured or squirted into the tube, conveniently by means of adevice in the nature of a grease gun. and it then becomes the functionof the apparatus of this invention to spread the coat ng uniformly overthe entire inside surface of the tube. I I

. The brush, indicated generally by the reference numeral 13,isdrivenby, a conventional air-turbine 14 which is connected at its intakeside with the flexible conduit 15 leading from the moisture separator 16which, in turn, is connected with a supply of compressed air.

In Figure 1 we have illustrated a compressor 17 having an air inlet 18and a dis- 7 charge pipe 19 leading to a reservoir or storage tank 20having a blow 03 valve 20 to maintain a supply of compressed air at apredetermined pressure.

The reservoir 20 mmunicates with the intake of the moisture remover 16through a pipe line 21 in m which a control valve '21 is provided. The

compressor 17 may be operated in any conventional manner as, forexample, by a motor 22.

Since the air turbine, when inuse, is 'inas side the tube, it followsthat the exhaust therefrom is discharged into the tube. The compressedair in the reservoir or storage tank 20 will carr more or less moisture,and

perhaps oil, an if the exhaustfrom the so air turbine were tocarry suchmoisture, (16-, posit thereof on the inner surface of the tube wouldpreclude the proper coating thereof since it is necessary that thecoating be applied directly to the clean, dry and bare'metal of thetube. The present apparatus avoids the difiiculty and secures thedesigned and a specially advantageousge- 'sult. The compressed air inentering the moisture remover 16 follows thefpath indicated bythearrowstherein. The. operation of the moisture remover per se is familiarto those skilled in the art. The current of entering air impinges uponthe surface of the elbow 23 and causes a part of the Water in the air toaccumulate on this surface. This water is drained from the surfacethrough a ipe 24 and into the water space .25, from w rob the water maybe removedairpasses downwardly, and this water is also discharged in thewater space 25. The

air in passing'around the lower edge of the cylinder 29'is subjected toa whip-snapping clean air then passes out '0 the discharge po 31 whichis connected to one end of the flexible tube 15.

The clean air, after it leaves .the moisture remover 16, is transmittedto the air turbine 14 by means of the flexible tube 15,

which is comparatively stout so that it may serve as a ban means and theend of which is threaded into the head 38.. v This 1 airturbine ofgenerally cylindrical form and of such size that it may fit looselywithin the. tube, may be of any conventional design.

The air makes its entry into the main housing 40 through the passage .35and then passes through the two supply ports 1,0 and 37 (Figs. 2 and 5).Suitably journaled in the mam housing, in bushings 57 and 58, is arotatable shaft 41 to which is secured intermediate its ends a rotor 42.This rotor 42 is positioned inside of a shell 43 (Fig. the boreofwhichls elliptical in' sh'ape. As

*shown in Fig. 5, the apertures 36-and 37 which constitute the supplyports of the turbine are so designed 'as'to cause the rotor to revolvein the direction indicated by the arrows. Bligh rotative speed isimparted to housing 0 is a circular plate (Fig. 2

'j air an the ports 51 an the shaft 41 by theaction .of the compressedair behind the paddles 45 carried in slots 46 in the rotor in theellipticalshel'l,

and two'of these paddles are always'unden pressure, the paddles alwa stending to' move outwardly to follow t e interior surface of theelliptical-shell. Positioned intermediate one end of the rotor 42 andthe a nipped with ports 51 and 52 (Figs.'6 and 73, which communicatewith the exhaust 53 and 54' in the housing 40.. The entering the supplyports 36 and 37, acts upon two ofthe paddles 45 causing.

the rotor 42 to revolve one-half arevolution. At the same the other twopaddles are-brought into upon, and so forth. eair, after. having actedupon the caddies dischar throu 52 and'thee h aust ferrmg now tothebrush, 'piv'otally secured to the free end of the shaft 41 are a of arms71 and 72. The arm 71 has a pair of lateral @1573 and 74 and the arm 2has apalr of lateral ears 75 and 76 which fit over the end of the shaft,and a pivot.

bolt 78 asses throu h these-ears and the end of t e shaft as own inFigure .8.

The arms 71 and 72 are drawn 7 ther at 80 (F 1g 2). and then extendparall to each itioii to be acted -otherin an outward direction, wherethey are formed into channel portions 81- and-82, respectively. Mountedin each channel 18 a base 83 of a brush 84.

end of the'arm 72 is a lateral projection 92 which passes throughtheopening 91 in the projection 90. The end of the projection 92,indicated by 'referencenumeral 93 in Fig. 2,

is bent into a hook to catch within the opening 91 and limit thedistance which the arms may be separated.

The brush as a whole is of a size to Qfit easily within the tube-and theconstruction and operation thereof is such that it will accommodateitself to varying sizes of'tubes within reasonable limits. It isapparent that when the shaft 41 revolves the arms 7 ,1 and 72 and thebrushes carried thereby will swing outwardly, due to centrifugal force,against the. inner wall or surface of. the tube 10. r T Y After the:coating, liquid form, has been, introduced into the tube as hereinhefore described, the brush is in the end of the tube, using theconduit 15 as a handle. The valve 9-1 is then opened, to supply thecompressed air and the brush revolves, the brush elements being pressedagainst the inner-surface of'the tube by centrifugal force. With thebrush revolving, it is fed slowly up the'length of the tube and backagain, and experience has demonacts as an agent 'to dry the spreadcoating,-

thus materially misting in even distribution and rapid rWe-claima 1. Incombination, a tube apparatus, a rotor driven by fair, and a brush withradially extending bristles expansibleby centrifugal .force therewithand driven thereb for appl" a' coating to the inner perip cry of the tuboth the brush and rotor be ng. adapted to enter the tube, theauexhaustof the said rotor to discharge into thesai u augmen drymgoecoa' .japlied thereto by the said brush. p

2. A tube coating apparatus comperisinfi an air turbine adapted to entera 'tu rotarybrush elements toand driven force.

3. A tube coating apparatus com r' an-air turbine adapted to enter atube and carried on the endof a flexible air condu'i and rotary brushelements hinged 'to and by said turbine to separate by centrifugal Ierner-a driven by said turbine to separate by centrifugal force.

I5 I an air turbine of generally cylindrical form 4.' A tube coatingapparatus comprising an air t-urbine of generally cylindrical formadapted to enter a tube and carried on the end of a flexible air conduitof lesser diam- 4 ete'r than said turbine, and rotary brush elementshinged to and driven by said turbine to separate by centrifugal force.

,5. A tube coating apparatus comprising an air turbine adapted to entera tube, and

a rotary brush hinged to and'driven by said turbine and having brushelements automatically moving outwardly when rotated. v, 6. A tubecoating apparatus comprising adapted to enter atube and carried on theend of a flexible air conduit also adapted to ente' the tube, saidturbine dischargingits exhaust into the tube, and a rotary brush hingedto the rotatin element of said turbine and having brus elementsautomatically moving outwardly when rotated. I

7. A tube coating apparatus com rising an air turbine adapted to enter atu e and carried on the end of a flexible conduit adapted for connectionto a source of com pressed air, and a brush expansible by centrifugalturbine, the exhaust from said turbine being restricted and dischargingdirectly into the tube toward the wall thereof in proximity to saidbrush. a

In witness whereof, we hereunto subscribe our names, this 9th day ofJuly, 1925.

a CHARLES- R MOORE. I v CHARLES 'STUBBS.

force carried and driven by said

